delivered the opinion of the court, ■ October 9th 1876.
While due effect should be given to the statutes authorizing amendments, yet care must be taken that they be not so used as to pervert their true spirit. None of the defendants in error were originally parties to the action of ejectment, the record of which they gave in evidence. They were substituted some two years after the writ issued. The original plaintiffs had no title and were nonsuited. The defendants in error did not derive title from them, but recovered on their own title solely. It was in nowise connected with the original plaintiffs. The so-called amendment was not the addition of names omitted through - mistake, nor of parties holding any joint interest with the original plaintiffs. There was no privity of title or interest between them. They were strangers to each other’s claim. The substitution was not authorized by the statute. That question, however, is not now before us on bill of exceptions. The substitution having been made, and the record being given in evidence in a subsequent suit, we may declare its effect.
Amendments depriving the-opposite party of any valuable right shall not be allowed; hence, when the name of a person was added as plaintiff in ejectment after suit brought, it was held that, if at the time of the amendment the title of the new party was barred by the Statute of Limitations, he could not recover: Trego et al. v. Lewis, 8 P. F. Smith 463; Kaul et al. v. Lawrence et al., 23 Id. 410. It follows therefore that, although the defendants in error were substituted without objection, yet they thereby acquired no rights relating back of their substitution. As to them, the action commenced when their names were put on the record. The first assignment is sustained.
The 2d, 3d, 4th, 10th and 11th assignments will be considered together. The .action of -ejectment was a legal averment of the right of the plaintiffs therein to the possession of the land. By theft recovery that right was established. In this subsequent action for mesne profits, the verdict and judgment are conclusive of their right to recover damages from the time their action commenced-down to the execution of the habere facias possessionem: Drexel v. Man, 2 Barr 271. But when they sought to recover for damages or profits prior to their action, the verdict and judgment were not conclusive as to such prior time. They were then required to prove theft title; for the record only showed that they recovered the term mentioned, from their substitution: Hare v. Fury, 3 Yeates 14; Bailey et al. v. Fairplay, 6 Binn. 450; Osbourn v. Osbourn, 11 S. & R. 58; Huston v. Wickersham, 2 W. & S. 308; Postens v. Postens, 3 Id. 183; Drexel v. Man, supra ; Sopp v. Winpenny, 18 P. F. Smith 80.
The evidence in the action of ejectment by which the right of possession was sustained, must not be confounded with the right itself. The direct issue in the case was their right to possession at *111the time they came on the record. . That issue having been found in favor of the plaintiffs therein, cannot be questioned in the present case. But it is well settled-that the estoppel of a.judgment extends only to the question directly involved in. the issue .and not to any incidental or collateral matter, though it may have arisen or been passed upon. The Duchess of Kingston’s Case, 11 Harg. State Trials 261; Moulton v. Libbey, 15 N. H. 480; Campbell v. Consalus 25 N. Y. 613; Hibshman v. Dulleban, 4 Watts 183; Lentz v. Wallace, 5 Harris 412; Martin v. Gernandt, 7 Id. 124; Lewis and Nelson’s Appeal, 17 P. F. Smith 153.
It is urged that the charge of the court below, in the action of ejectment affirmed here, is a part of the record, and that it and the other proceedings in that case show the same title now set up by the plaintiffs in error was there adjudged to be invalid.
It is true the charge of the court and the evidence may be made a part of the record for the purpose of reviewing the correctness of the rulings in the particular case: Northumberland Bank v. Eyer, 8 P. F. Smith 97; but at common law they are no part of the record: Erb v. Scott, 2 Harris 20; Hageman et al. v. Salisberry, 24 P. F. Smith 280. They are preliminary or incidental to the main issue concluded by the verdict and judgment. For the purpose of enforcing the particular judgment they may be. deemed a part of the.record: Hageman v. Salisberry, supra. Their conclusive effect in a .collateral suit is another question.
• It was held in Packet Co. v. Sickles, 5 Wall. 592, and in Coleman’s Appeal, 12 P. F. Smith 252, that the plea of judgment recovered may be sustained by a mixed matter of record and of fact. But when extrinsic evidence is given for that purpose, it must be consistent with the record, and unless it be shown that the verdict and judgment necessarily involved its consideration, it will not be conclusive.
Thus far-we have considered the effect to be given to a judgment in those cases where one judgment is conclusive. The verdict and judgment in this ejectment did not necessarily involve'the title nor the possession prior to the commencement of the action. They were conclusive for the recovery of mesne profits only, and for that purpose only from the time of the commencement of the suit.
In a second action of ejectment between the same parties, the verdict and judgment would not be conclusive. Every fact and conclusion found in the first suit might be controverted in the second. Hence when, in this action, the defendants in error claimed for mesne profits prior to bringing their suit in ejectment, they opened the question of their title and of the possession of the opposite party for such prior time, as fully as it would have been by a second action of ejectment. Neither the prior judgment in ejectment nor any of the proceedings therein estopped the plaintiffs in error from having their rights again passed upon, nor from' having the. same evidence *112considered by another jury. The assignments are therefore substantially sustained.
The fifth assignment relates to the plaintiffs in error being charged in this action with the money which they had received from Seyfert, McManus & Co.
In an action for mesne profits the plaintiff may recover for the fair rent or yearly value of .the premises, and for injury done thereto: Huston v. Wickersham, supra. Compensation is the proper measure of damages: Morrison v. Robinson, 7 Casey 456. The action is equitable in its character: Zimmerman v. Eshbach, 3 Harris 417. Hence a boná, fide occupant under claim of title who has made permanent and valuable improvements, may show them to be a full compensation for the use of the premises: Morrison v. Robinson, supra. The fact that the plaintiffs in error had let the premises for a term of fifteen years at an annual rental of $2000, besides the payment of royalty on each ton of iron ore mined, and received the rent for one year, did not necessarily give the defendant in error the right to recover that sum. It appears that no ore was mined by the lessees during the time for which the plaintiffs in error are liable for mesne profits. By their eviction they became unable to fulfil their covenants in the lease. Their lessees acquired a right of action against them for damages which may equal or exceed the whole sum they have received. Then if the premises were in nowise injured by the lessees, and they took no ore therefrom, we cannot see that the $2000 received by the plaintiffs in error establishes a correct basis for fixing the just rental value of the premises. The receipt thereof under the circumstances establishes no just compensation for the rights withheld, nor for injuries sustained. The point covered by this assignment should have been affirmed.
We are not furnished with the draft showing the “ red marked line” referred to in the eighth assignment. We understand it is also called the “ Pine Grove line.” John Evans testifies: “ taking it for granted that the line marked with red marks is the western boundary of the Cox tract, there would only be about twenty acres of the Seyfert and McManus lease on the Cox tract.” David Peelor testifies, “ taking it for granted that the Pine Grove line is the western boundary of the Cox tract, there would only be about twenty or twenty-five acres of the Seyfert & McManus lease on the Cox lands.” Both of these witnesses were surveyors and had surveyed the lands in controversy. The number of acres was for the jury to find, and the learned judge erred in inadvertently assuming fifty-two acres to be the correct quantity.
The evidence covered by the thirteenth assignment was offered for the purpose of showing substantially the increased value given to the premises by the improvements and expenditures made by the plaintiffs in error in developing the mines. The witness knew the premises both before and after those improvements were made. He *113had had large experience in the ore and iron business. He knew the character of those improvements. He knew the ore banks in question, and was familiar with mining operations in that vicinity. ■He therefore, had sufficient knowledge to form an intelligent opinion of the value of the premises both before and after their development. Those two valuations being ascertained certainly threw some light on the value of the improvements. Other testimony had shown some of the improvements to be of such a permanent and valuable character as to make them the proper subject of consideration by the jury. Morrison v. Robinson et al., supra. We do not think the mode of proof was so objectionable as to justify the exclusion of the testimony.
In so far as the other assignments are not covered by what we have already said, they are not sustained.
Judgment reversed, and a venire facias de novo awarded.